That's really good report ! 850W for 4*GPU dual mining is really good in my opinion

And your ETH Hashrate is good too : best hashrate I've heard on RX580 are around 31MHs, but you're really close to it

If your rig is stable (and that's the most important part), just stick to this and be happy

I have a question/suggestion though : if I were you, I would not use a USB stick to run SimpleMiningOS from. I've had some troubles with low quality USB sticks : their lifespan seems quite low. Wouldn't it better to run it with the SSD ?